Re: SPACE: Anti-Nuke Group Demands Sun Be Turned Off

From: Eliezer S. Yudkowsky (sentience@pobox.com)
Date: Wed Jan 22 2003 - 04:28:12 MST


Dossy wrote:
> On 2003.01.21, Damien Broderick <thespike@earthlink.net> wrote:
>
>>Excellent point. In fact, I recall that the mean time to the surface for a
>>photon from the core is not just thousands of years, but a *million* years.
>>[!!]
>
> That's a comforting thought. The Sun could have blinked out hundreds of
> thousands of years ago, and we have absolutely no idea? :-)

I'd expect the Sun's light to slowly diminish along a curve, rather than
blink out all at once. So even if it blinked out hundreds of thousands of
years ago, it will shine long enough for my purposes.

But I've heard thousands, not millions. *google google*. Okay, millions.
http://www.ucolick.org/~mountain/AAA/answers/physics/ph10.html
http://www.howstuffworks.com/sun2.htm

 From http://www-astronomy.mps.ohio-state.edu/~dhw/Intro/lec7.html
>
> If we divide the heat energy of the sun's atoms by the observed luminosity of the sun (the rate at which this energy escapes), we find that the sun's energy supply would be exhausted in about 30 million years.
>
> The sun can replace some of this energy by gravitational contraction (which increases the central pressure and therefore heats up the gas in the middle), but this process can only increase the lifetime by about a factor of two.

-- 
Eliezer S. Yudkowsky                          http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence


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